1. Field of the Invention
This invention relates to an automatic item handling system and methods for handling and transporting items in a facility designed with a flow through storage system. More specifically, the invention relates to automated remote transport and item handling systems that revolve around a network of centrally controlled remote vehicles that handle the storage and retrieval of boxes in a refrigerated flow through storage facility.
2. Related Art
There is a need for an automated item handling system for storing and retrieving items, specifically boxes, that can be implemented in a facility already equipped with a refrigerated flow through storage system and that can be implemented without major modifications to the existing facility. A flow-through storage system is an array of open racks which comprises a plurality of perpendicular crossing beam members that form the rectangular-shaped open storage racks. The term xe2x80x9cflow-throughxe2x80x9d is used because items are stored through the rear of the storage racks into a bin and the items flow through to the front of the rack where they can be retrieved from the bin. The items are conveyed from the rear of the bin to the front by a conveyance means. A xe2x80x9cbinxe2x80x9d is a single open flow through channel or it can be described as a single open shelf in the rack.
Refrigerated meat processing flow through storage facilities are typically maintained at 32xc2x0 F. or lower, therefore any automated system for storage and retrieval in such a facility must be able to operate under those conditions, which may limit the use of systems requiring hydraulic fluids to function.
A typical storage facility within a typical meat processing facility is centrally located with respect to the production and shipping areas. Also, a typical high volume meat processing flow through storage facility may handle upwards of 60,000 boxes on both the input storage and output retrieval shipment sides on a given day. Therefore, up to 60,000 boxes per day are transported from the meat processing production area and stored in flow through storage bins (lumping) where they remain until they are retrieved (picking) and delivered to a shipping area to fill orders. There is a need to automate the handling of the storage and the retrieval of boxes in a flow through storage facility having a high throughput in order to handle such large quantities efficiently.
Other more modern types of storage facilities include individual bin storage and conveyorized box storage facilities with automated box handling systems. However, some less modern existing storage facilities are designed with flow through storage racking. There are at least two major economic reasons why the existing storage facilities with flow through systems should be maintained with minimum modification rather than converted to accommodate a more modern and different type of storage system.
One economic reason is that flow through facilities typically have a greater storage efficiency in terms of boxes stored per cubic feet of storage volume as compared to modernized individual bin and conveyorized storage facilities with automated box handling.
A second economic reason is that typical automated item handling systems are not designed to meet the unique requirements of a facility that was previously designed to accommodate a flow through storage system, therefore the facility would have to be significantly modified to accommodate a more modern item handling system.
Modification of an existing storage facility, with an existing flow through storage racking system, to accommodate a more modern and different type storage system would be very costly. Therefore, an automated item handling system that can be integrated into an existing flow through storage facility without having to implement major modifications to the facility is needed.
In addition to needing a system that can be integrated without major modifications, there is a need to maintain a safe working environment for the people working in the facility, both when the automated system is operating and when it is not operating. The aisles between flow through storage bins in some existing flow through storage facilities are very narrow (approximately 35 in wide) as they were not designed to allot dedicated space for an automated item handling storage system. Therefore any automated system that requires dedicated floor space for a transport and handling means would further limit the usable floor space between aisles. Limited floor space on which workers can maneuver inherently makes for hazardous work conditions, causing tripping accidents and accidental collisions that may result in injury.
An automated system that inputs or stores boxes into storage bins (lumping) is needed and the same is true for a system that retrieves the boxes for removal from storage for shipping (picking). In addition, however, a typical flow through facility, boxes are stored in flow through bins on skids which are carried on skate conveyors from the input storage (lumping) end of the bin to the output retrieval (picking) end. Therefore, integrated into a flow through storage facility, there is a need for a method and system to remove empty skids from the output end (picking end) and stow them for future use and there is a need for a method and system to insert additional empty skids into the input end (lumping end) when all the skids in the flow through bin are filled to their maximum capacity. Skid handling is an important aspect of any flow through storage item handling system because the picking and lumping will come to a halt until an empty skid is removed when needed or inserted when needed. This function is currently manual and reduces the efficiency of the operation.
A typical automated item handler system that is utilized in a storage facility is designed for a modernized storage facility having individual bin storage or a facility having conveyorized box storage integral with a network of conveyors that transport items to and from storage locations. A design of this type does not meet the requirements outlined is above for the automation of an existing flow through storage facility. For example a typical flow through facility may have ceilings no higher than 7 ft.; the lowest level bin is just above floor level; and the aisles are typically no wider than 35 in. Typical automated storage handling systems are not easily integrated into such facilities because they either entail large conveyor systems requiring a lot of space or they are remote vehicles that require large aisles and dedicated floor space for a guidance means.
A review of prior art patents did not reveal any patents that specifically address the needs of a flow through storage facility. However, there are some prior art patents that address box handling functions for a storage facility that are typical of those used in individual bin or conveyorized storage facilities. In addition, some patents address the problem by the use of a centralized network of Box Handling Robots.
For example, U.S. Pat. No. 4,492,504 issued Jun. 8, 1985 to Hainsworth addresses an unmanned guided vehicle that is propelled along a path by a traction mechanism. It is clear that the apparatus of this patent is designed to accommodate an individual open bin storage system. However this patent is worthy of noting because it shows an apparatus that performs the general tasks of lumping and picking in a storage facility and is representative of how a facility with an individual bin storage system is automated. However the apparatus shown in Hainsworth ""504 does not have the elements or the functionality to meet the paticular requirements, as outlined above, for automating an existing flow through storage facility.
The actuator arm of Hainsworth is designed to retrieve one box at a time and there is only one arm per robot, thus multiple items from a skid could not be retrieved simultaneously. It will be difficult to maintain a desired flow of handling 60,000 items per day on both the input (lumping) end and the output (picking) end with the Hainsworth design. Also, in a typical flow through system, boxes are stored on skids that rest on skate conveyors. Also, boxes are stacked in multiple rows usually two rows high. Therefore, if the one arm system shown in Hainsworth is used and the arm attempts to remove a box on the top row, it is likely that the box underneath will move due to friction, or possibly the entire skid will move. There is no means to prevent the lower tier box or the skid from moving.
Also, the guidance system of Hainsworth comprises a radiation source that causes a guide line to reflect or emit a guidance signal. Hainsworth also discloses alternative guidance methods such as a fixed rail system or a buried wire guidance system. Either of the disclosed guidance methods will require dedicated space for the tracking means. This would further narrow the useable floor space between flow through bins even when the remote vehicle is not passing through. Also, either guidance method will require modifcation to the floor of an existing facility, or as a minimum the floor would have to be leveled and repaired to eliminate dips or cracks in the floor prior to installing the radiating strip. However, in the case of a buried wire guidance method, a portion of the floor would have to be torn up in order to install the wire. Either method is contrary to the requirements outlined above for automating an existing flow through facility because of the extensive modifications and safety impacts.
A way is needed to reliably lump and pick items in an existing flow through storage facility and to make a seamless transport of boxes from production to storage and onto shipping. There is also a need for the item handler to automatically identify the item to be lumped or picked so that travel time and cycle time is minimized for a more efficient operation.
It is in view of the above problems that the present invention was developed. It is an object of this invention to automate the lumping and picking of items in an existing flow through storage facility efficiently and with minimal impact to the existing facility.
It is also an object of this invention to maintain the current available floor space between the flow through storage bins in order to assure easy and safe access.
It is also an object of this invention to remove empty skids from the flow through bin, stow them as needed and then retrieve and reinsert empty skids into the flow through bins as needed.
It is also an object of this invention to more reliably automate an existing storage facility with a centrally controlled network of semi autonomous lumping and picking means that make a seamless transport of boxes from production to storage and onto shipping.
The invention satisfies the above objects by providing a method and apparatus for the automation of an existing flow through facilityxe2x80x94that is providing a centrally controlled network of semi-autonomous mobile robotic vehicles having on-board embedded controls. The robotic vehicle is adapted with a means for storing boxes in (lumping) and retrieving boxes from (picking) flow through storage bins and is adapted with a means for stowing empty skids and re-inserting empty skids into flow through storage bins. The robotic vehicle has an on-board communication means that is adapted to transmit to and receive signal messages from a centrally controlled network that coordinates the transport of boxes by the remote vehicle from production, to temporary flow through storage and onto shipping. A central data parser is the central point where all information external to the network is received. The data is processed and top level tasks are assigned to central process controllers located on every floor having flow through storage bins. The central process controllers then assign specific tasks to the remote vehicles whereby the on-board controller executes specific picking and lumping operations. The preferred embodiment of the robotic vehicle can be powered by an electric motor and has four wheels that ride on a pair of over-head track rails wherein one of the track rails can be adapted to provide an electrical power connection to the vehicle. The vehicle can be adapted with a trolley type connection frame that can serve both as a connection to the main electrical power and provides moment stability to the vehicle to prevent tipping. In this preferred embodiment, the vehicle is freely suspended hanging from the rails and never touching the floor. The vehicle can also be adapted with collision avoidance sensors for determining vehicle position with respect to other objects and with a means to read a code placed on the exterior of the box for product verification. The vehicle also incorporates absolute encoders to monitor actual distance traveled by the vehicle in order to positively locate the vehicle in the network of storage bins at all times.
The inventor has determined that a centrally controlled network of remote robotic vehicles is effective in automating an existing refrigerated flow through strorage facility for the meat processing industry. The remote vehicle is integrated with the flow through storage bins and a conveyor system for transporting boxes to shipping and from production.